Serjoscha Evers
@sirjoscha.bsky.social
Director of Urwelt-Museum Oberfranken, Bayreuth, a regional museum of the Bavarian State Collections of Natural History | Pala(e)ontologist with reptilian bias | Associate Editor for Journal of Systematic Palaeotology | turtle evolution
#2025SVP ! If you want to get an idea of the major steps of 🐢turtle🐢 evolution, come to see my talk on Friday, Nov 14, 8:30 AM, Hall 8. My student Guilherme Hermanson talks just before me (8:15). 4 years of macroevolutionary research on turtles went into our talks, covering many unpublished results.
November 5, 2025 at 11:25 AM
#2025SVP ! If you want to get an idea of the major steps of 🐢turtle🐢 evolution, come to see my talk on Friday, Nov 14, 8:30 AM, Hall 8. My student Guilherme Hermanson talks just before me (8:15). 4 years of macroevolutionary research on turtles went into our talks, covering many unpublished results.
@seishirotada.bsky.social & colleagues explore the evolution of rostral vasculature in turtles – a topic close to my personal interests due to my carotid and overall skull-CT work. Fantastic images in this one!
link.springer.com/article/10.1...
link.springer.com/article/10.1...
October 7, 2025 at 8:20 AM
@seishirotada.bsky.social & colleagues explore the evolution of rostral vasculature in turtles – a topic close to my personal interests due to my carotid and overall skull-CT work. Fantastic images in this one!
link.springer.com/article/10.1...
link.springer.com/article/10.1...
New papers in the Turtle Evolution Symposium Proceedings! Juliette Menon & Walter Joyce published a paper re-describing a Cretaceous sea turtle – but the main story here in my opinion is the homology statements regarding neural positions. Brilliant student work!
link.springer.com/article/10.1...
link.springer.com/article/10.1...
October 7, 2025 at 8:15 AM
New papers in the Turtle Evolution Symposium Proceedings! Juliette Menon & Walter Joyce published a paper re-describing a Cretaceous sea turtle – but the main story here in my opinion is the homology statements regarding neural positions. Brilliant student work!
link.springer.com/article/10.1...
link.springer.com/article/10.1...
For #FossilFriday, here is the holotype of Pistosaurus longaevus (UMO BT-682) from the collections of the Urwelt-Museum Oberfranken in Bayreuth. I’ve removed the specimen from exhibits to have it photographed for a research project.
September 26, 2025 at 2:20 PM
For #FossilFriday, here is the holotype of Pistosaurus longaevus (UMO BT-682) from the collections of the Urwelt-Museum Oberfranken in Bayreuth. I’ve removed the specimen from exhibits to have it photographed for a research project.
The study was conducted by @spichergael.bsky.social & colleagues (@feikosaur.bsky.social) & published today in @mfnberlin.bsky.social's Open access journal Fossil Record. Congrats to all authors! It's available here: fr.pensoft.net/article/1542...
Fossil & artwork to be exhibited at UMO in future.
Fossil & artwork to be exhibited at UMO in future.
September 25, 2025 at 2:36 PM
The study was conducted by @spichergael.bsky.social & colleagues (@feikosaur.bsky.social) & published today in @mfnberlin.bsky.social's Open access journal Fossil Record. Congrats to all authors! It's available here: fr.pensoft.net/article/1542...
Fossil & artwork to be exhibited at UMO in future.
Fossil & artwork to be exhibited at UMO in future.
News @ Urwelt-Museum Oberfranken (UMO) in Bayreuth: new ichthyosaur, Eurhinosaurus mistelgauensis, named today after UMO's prime excavation site, the Jurassic clay pit Mistelgau. @olorotitan.bsky.social beautifully reconstructed the to-be fossil on a belemnite battleground typical for the locality.
September 25, 2025 at 2:36 PM
News @ Urwelt-Museum Oberfranken (UMO) in Bayreuth: new ichthyosaur, Eurhinosaurus mistelgauensis, named today after UMO's prime excavation site, the Jurassic clay pit Mistelgau. @olorotitan.bsky.social beautifully reconstructed the to-be fossil on a belemnite battleground typical for the locality.
The Nuremberg Zoo has mata mata (Chelus fimbriatus) turtles!! 🐢😍 I remember my first Chelus skull encounter as a major „WTF nature“ moment - so cool to see a living one at least.
August 31, 2025 at 11:23 AM
The Nuremberg Zoo has mata mata (Chelus fimbriatus) turtles!! 🐢😍 I remember my first Chelus skull encounter as a major „WTF nature“ moment - so cool to see a living one at least.
And, Tyler Lyson and his team published a new pan-chelydrid turtle from the early Danian of Colorado, which I had the pleasure to see in Tyler's office pre-publication last year. Welcome, Tavachelydra stevensoni!
sjpp.springeropen.com/articles/10....
sjpp.springeropen.com/articles/10....
August 6, 2025 at 5:22 AM
And, Tyler Lyson and his team published a new pan-chelydrid turtle from the early Danian of Colorado, which I had the pleasure to see in Tyler's office pre-publication last year. Welcome, Tavachelydra stevensoni!
sjpp.springeropen.com/articles/10....
sjpp.springeropen.com/articles/10....
Interestingly, our (preliminary) data suggest that sexual shape dimorphism in turtles is negligible when compared to ontogenetic change & interspecific differences even b/w closely related species.
August 5, 2025 at 8:24 PM
Interestingly, our (preliminary) data suggest that sexual shape dimorphism in turtles is negligible when compared to ontogenetic change & interspecific differences even b/w closely related species.
Our main question: How big are turtles in terms of shell size (an oft available & easy to measure property) when ‘adult shape’ is reached. When we define adult shape as having reached 85% the shape difference b/w small juveniles & extremely large adults, the answer is at 65% max shell length
August 5, 2025 at 8:24 PM
Our main question: How big are turtles in terms of shell size (an oft available & easy to measure property) when ‘adult shape’ is reached. When we define adult shape as having reached 85% the shape difference b/w small juveniles & extremely large adults, the answer is at 65% max shell length
We then developed ontogenetic shell shape curves, analog to growth curves. Shell shape (measured w 2 methods) is plotted against shell size. These plots show generally that shell shape changes through growth, but shell shape change slows down to converge on an ‘adult shape’
August 5, 2025 at 8:24 PM
We then developed ontogenetic shell shape curves, analog to growth curves. Shell shape (measured w 2 methods) is plotted against shell size. These plots show generally that shell shape changes through growth, but shell shape change slows down to converge on an ‘adult shape’
Disparity between species is lower when only juveniles are considered, whereas intermediate sized & adult turtles have significantly increased disparity. This suggest that many lineage specific features of shell shape that cause this disparity appear only during postnatal ontogeny.
August 5, 2025 at 8:24 PM
Disparity between species is lower when only juveniles are considered, whereas intermediate sized & adult turtles have significantly increased disparity. This suggest that many lineage specific features of shell shape that cause this disparity appear only during postnatal ontogeny.
We took a large pre-existing turtle shell shape dataset fr Tristan Stayton’s work 🙏 We identified species specific datasets w large size variance to test for ontogenetic patterns - & they exist. Most turtles start w rounded shells as juveniles, possibly a developmental constraint related to swimming
August 5, 2025 at 8:24 PM
We took a large pre-existing turtle shell shape dataset fr Tristan Stayton’s work 🙏 We identified species specific datasets w large size variance to test for ontogenetic patterns - & they exist. Most turtles start w rounded shells as juveniles, possibly a developmental constraint related to swimming
If you are in Bayreuth, please stop by our museum - and if you are interested in collection visits, please reach out!
This is a permanent academic position in palaeontology - I am happy to have made it this far & am thankful to a great many people who helped me along the way 🙏
This is a permanent academic position in palaeontology - I am happy to have made it this far & am thankful to a great many people who helped me along the way 🙏
August 3, 2025 at 7:39 PM
If you are in Bayreuth, please stop by our museum - and if you are interested in collection visits, please reach out!
This is a permanent academic position in palaeontology - I am happy to have made it this far & am thankful to a great many people who helped me along the way 🙏
This is a permanent academic position in palaeontology - I am happy to have made it this far & am thankful to a great many people who helped me along the way 🙏
With the museum team, my job will be to renew the exhibits, organize special exhibits, continue & expand excavations in Mistelgau, curate and organize collections, facilitate research & continue my own research. The job is very multifaceted, & I am excited for all parts of it!
August 3, 2025 at 7:39 PM
With the museum team, my job will be to renew the exhibits, organize special exhibits, continue & expand excavations in Mistelgau, curate and organize collections, facilitate research & continue my own research. The job is very multifaceted, & I am excited for all parts of it!
I am happy to announce that as of this month, I am the new director of the Urwelt-Museum Oberfranken, with its >600m2 exhibit halls in the center of Bayreuth and a rich Triassic-Jurassic marine reptile collection from Muschelkalk deposits & Mistelgau alongside a rich Jurassic plant collection & more
August 3, 2025 at 7:39 PM
I am happy to announce that as of this month, I am the new director of the Urwelt-Museum Oberfranken, with its >600m2 exhibit halls in the center of Bayreuth and a rich Triassic-Jurassic marine reptile collection from Muschelkalk deposits & Mistelgau alongside a rich Jurassic plant collection & more
The latest Turtle Evolution Symposium paper in our TES Special Volume: Rollot et al. describe a new species of carettochelyid turtle from the Miocene of Egypt, and name it Allaeochelys meylani, after Peter Meylan, who published a lot of trionychian research.
sjpp.springeropen.com/articles/10....
sjpp.springeropen.com/articles/10....
June 21, 2025 at 11:18 AM
The latest Turtle Evolution Symposium paper in our TES Special Volume: Rollot et al. describe a new species of carettochelyid turtle from the Miocene of Egypt, and name it Allaeochelys meylani, after Peter Meylan, who published a lot of trionychian research.
sjpp.springeropen.com/articles/10....
sjpp.springeropen.com/articles/10....
Today, I submitted my habilitation at the Uni of Fribourg! I taught more than 100 hours of palaeontology & historical geology over the last years - happy to finally have gotten all requirements together…
June 3, 2025 at 5:23 PM
Today, I submitted my habilitation at the Uni of Fribourg! I taught more than 100 hours of palaeontology & historical geology over the last years - happy to finally have gotten all requirements together…
@heatherfsmith.bsky.social and colleagues published on a new Maastrichtian ctenochelyid sea turtle, Asmodochelys leviathan.
link.springer.com/article/10.1...
link.springer.com/article/10.1...
May 20, 2025 at 9:48 AM
@heatherfsmith.bsky.social and colleagues published on a new Maastrichtian ctenochelyid sea turtle, Asmodochelys leviathan.
link.springer.com/article/10.1...
link.springer.com/article/10.1...
Turtle-free week! On a family holiday in the Allgäu. Learning how to ski in parallel with my daughter and her cousins.
January 29, 2025 at 9:20 AM
Turtle-free week! On a family holiday in the Allgäu. Learning how to ski in parallel with my daughter and her cousins.
In their data, the flat-shelled fossil turtle Basilemys plotted as one of the highest domed species - & we found more problems w data & analyses when dissecting the study. After data corrections & usage of PCMs, we show that the central claims of the original paper cannot be upheld.
January 3, 2025 at 6:25 PM
In their data, the flat-shelled fossil turtle Basilemys plotted as one of the highest domed species - & we found more problems w data & analyses when dissecting the study. After data corrections & usage of PCMs, we show that the central claims of the original paper cannot be upheld.
Successful weekend when the little one says “Mathilda happy” before she falls asleep on the train back :)
November 17, 2024 at 1:04 PM
Successful weekend when the little one says “Mathilda happy” before she falls asleep on the train back :)
Nice weekend vibes from Graubünden! Mountains are always best for re-charging 🗻☀️😍
November 16, 2024 at 2:43 PM
Nice weekend vibes from Graubünden! Mountains are always best for re-charging 🗻☀️😍